Welcome to the impossible and incredible world of the Colostle. The Colostle is a castle so big that there are oceans, mountains and cities within its rooms! There is no 'outside' to the Colostle, everything is within. And stalking these Roomlands, are the Rooks, huge walking stone castle towers that attack anything they see, but hold the Rookstones, the only source of magic in this world.

The Colostle seems to exist infinitely in all directions, rooms beyond rooms, floors above floors. Although after some climbing one can reach the rooftops or battlements, the view that destination affords is one of tiles and towers to the horizon.​

Everyone's experience of the Colostle is different, exploring a different part of this impossible and infinite structure, but there are regions, cultures and specific types of rooms to discover out there, beyond what is known and mapped.